If you allow for autonomously acting AIs, then you could have Friendly autonomous AIs tracking down and stopping Unfriendly / unauthorized AIs.
This of course depends on people developing the Friendly AIs first, but ideally it'd be enough for only the first people to get the design right, rather than depending on everyone being responsible.
Importantly, the situation isbelow the immanent existential threat level.
It's unclear whether AI risk will become obviously imminent, either. Goertzel & Pitt 2012 argue in section 3 of their paper that this is unlikely.
I would suggest a combination of generality and agency. And what problem domain requires both?
Business (which by nature covers just about every domain in which you can make a profit, which is to say just about every domain relevant for human lives), warfare, military intelligence, governance... (see also my response to Mark)
then you could have Friendly autonomous AIs tracking down and stopping Unfriendly / unauthorized AIs.
Somehow that reminds me of Sentinels from X-Men: Days of Future Past.
There have been a couple of brief discussions of this in the Open Thread, but it seems likely to generate more so here's a place for it.
The original paper in Nature about AlphaGo.
Google Asia Pacific blog, where results will be posted. DeepMind's YouTube channel, where the games are being live-streamed.
Discussion on Hacker News after AlphaGo's win of the first game.